Cardiac dysfunction is the most common cause of death in elderly people. Thus far, cardiovascular aging has been considered a continuous and irreversible process. Although mammalian models for age-related cardiac dysfunctions do exist, it is recognized that it will be necessary to discover new gene functions and elucidate their relationships to known cardiac diseases and disease genes, in order to achieve a better understanding of the cardiac aging. Such an understanding is prerequisite for developing more effective treatments. We propose to use the Drosophila fly model, to study age-related cardiac function and dysfunction, and to identify new genes that affect cardiac performance when altered in old animals. The Specific Aims are: (1) to establish the fly heart as a model for age-related changes of cardiac performance, (2) to carry out genetic manipulation to study age-related cardiac performance (Myosin heavy chain (Mhc) isoforms, Parvalbumin and large-scale screens to identify new genes), and (3) to examine age-related cardiac and muscle function of dystrophin complex genes in the fly model.